Scientists Worldwide Making Nanotech A Reality 

CHARLES BICKERS IN TOKYO / Far Eastern Economic Review 18jan01

AMID THE CLUTTER of microscopes and gas cylinders in the physics department of Hong Kong's University of Science and Technology, Wen Weijia demonstrates a laboratory party trick with a small dish of gooey white paste.

Wen flicks a switch to run a tiny electric field through the paste. Instantly the paste turns solid. He switches the field off and just as quickly the paste is liquid again. It's a long-recognized phenomenon. The paste consists of small electrically sensitive particles suspended in silicon oil. When an electric field is applied, the particles respond by organizing themselves in chains, giving rigidity to the mixture.

Such a material has a variety of uses. Most significantly, it could act as a low-friction, low-maintenance clutch -- engaging and disengaging a drive shaft without complicated hydraulics and extra moving parts -- in cars and in industrial manufacturing. But until now nobody has developed a paste reliable enough for commercial use. Wen's secret? Pre-treating the surface of the particles in the paste at an atomic level -- a technique called nanotexturing. This incredibly fine layer of uniformly formed molecules on the surface of the particles specifically enhances their electrical response.

"It's about 10 times stronger than anything else we know of," says Wen.

He has used similar nanotexturing techniques to give a flexible plastic sheet an enhanced ability to absorb microwaves or radar waves -- producing a tool with many potential applications in telecommunications, consumer electronics and defence.

Welcome to the cutting edge of nanotechnology, the science of directly engineering and manipulating the very atoms and molecules that make up matter. The term nanotechnology refers to the scale: a nanometre is one billionth of a metre. By altering many everyday materials such as carbon, metals or plastics at the atomic level, scientists can harness a whole new world of electrical, chemical and structural possibilities that could revolutionize a host of industries.

It's a branch of science that has promised much for the last decade but has delivered little to the real world beyond big ideas and interesting microscope photos. But that's changing. Equipped with a better understanding of the atomic-level properties of materials and the technology to view the nano-world, scientists worldwide are making applications of nanotech a reality. While the United States is the clear leader in nanotech science, industrial companies in Asia, notably Japan's Hitachi, NEC, Fujitsu and Mitsubishi and South Korea's Samsung, are fast realizing that making it big in the 21st century means mastering technology at the lowest end of the scale.

Products such as better computer displays and cellphone batteries will incorporate nano-engineered materials to start the ball rolling. Further down the line are improved electronic circuits and biotech tools the size of DNA strands. Nanotech's importance is broad. While the electronics industry is excited at the prospect of using nanotech to develop faster computer processors and vast computer memory storage, the biotech industry is keen to see how it can use tailored molecules and incredibly small devices to work inside the human body. The manufacturing industry, meanwhile, sees nanotech techniques as a new tool for producing stronger, lighter, more flexible materials.

David Tomanek, a visiting professor at the Tokyo Institute of Technology, has just finished tours of Japanese and South Korean companies and universities. He's eager to spread the word that nanotechnology is no longer a drawing-board proposition. He now packs a PowerPoint presentation called Making Your Money Work on the Atomic Scale, which is aimed squarely at opening industry's eyes to the new science.

"We're now firmly at the stage that leaders in any industry need to sit up and listen," says Tomanek. "It used to be that I talked to a car manufacturer and he listened politely. Now I tell him we have a material many times stronger and lighter than steel, and he's all ears."

One of the fastest out of the gates with a nano-product demonstration has been Samsung Electronics of South Korea. It's using the electrical properties of nano-engineered carbon to produce a new type of display for televisions and computers that uses far less power than current models. Having displayed a prototype last year, Samsung expects to field a commercial version by 2003.

Samsung is also the world's leading maker of memory chips, a factor that's driving extensive nanotech research at the company's labs. "The display is our first step into the nanotechnology world, but we expect to see much more from the technology in the electronics field," says Kim Jong-min, executive director of the Samsung Advanced Institute of Technology, the subsidiary that's pioneering the research.

Specifically, says Kim, the company believes nanotech may enable it to build computer memory chips in the terabit class -- ones capable of storing a trillion bits of data. The latest generation of chips is in the gigabit class, holding a billion bits of information.

Fujitsu, another leading semiconductor company, recently announced it would open a nanotechnology research centre in Kawasaki, near Tokyo. The company says its research priorities are to develop semiconductor alternatives to silicon for advances in computer memory and processing.

Such advances will likely come from nanotechnology's poster child, the carbon nanotube. This is a promising new form of carbon discovered by Sumio Iijima, a scientist at Japanese electronics company NEC. During an experiment in 1991 in which he passed high voltages of electricity through carbon, Iijima spied amid the resulting powdery residue a patch of astonishingly tiny threads of carbon.

Carbon most commonly appears in nature either as graphite or diamond, both useful in their own ways. What Iijima discovered was a third form of carbon. Essentially it's a sheet of single-layered carbon atoms that folds itself into a tube under the kind of electrical stress that Iijima applied. Once in that shape, it's extremely stable and strong.

In fact, carbon nanotubes are up to 100 times stronger than steel. They're also ideal conductors of heat and electricity, chemically inert and nontoxic, and have an extremely high melting point. All this has been theorized for years, but what has been slow to appear is the ability to use these properties. While the nanotubes are strong, they measure less than a few thousandths of a millimetre. Only now are scientists beginning to find ways to bind the tubes together as rope, or integrate them into other materials to increase the strength of the combined product.

Expected applications of carbon nanotubes include ultra-small electronic circuitry, biologically inert delivery vehicles for drugs, ultra-strong lightweight materials to replace or augment steel or composites, high-performance electrodes for batteries or flat-panel TV and computer displays, and a safe way to store hydrogen.

HKUST's Chan also points to the potential for a type of capacitor, which is a device that can store an electrical charge by placing two conductors close together with an insulating layer. Theoretically a nanotube could be multilayered to form a very small and efficient capacitor called a super-capacitor. Such devices could be instantly recharged with large amounts of electrical energy, which could then be drawn off slowly by an electric motor. So while today's electric vehicles take hours to recharge their batteries, a quick top up into a super-capacitor could eventually make them faster to "refuel" than conventional petrol-driven cars.

Nanotubes have allowed HKUST to justly stake a rare claim for Hong Kong to be a scientific leader, with Zikang Tang and Ning Wang becoming the first in the world to reliably produce the smallest possible form of carbon nanotubes. Normally, carbon nanotubes look like a heap of tangled woollen strands of widely varying length. By growing the tubes inside special crystals, Wang and Tang managed to produce them side by side in orderly rows and sizes.

Order is important for nanotech to shift into overdrive in industry. For instance, carbon nanotubes of a certain diameter may have specific attractive qualities, but reliably building just one diameter of nanotube is difficult. Without the ability to build nano-objects at will, placing atoms precisely where they're needed, many potential applications will remain unfulfilled.

Take, for example, nanotechnology's role in the computer industry. Such advances are important because conventional consumer electronics are a decade away from a manufacturing brick wall: At a time of increasing demand for smaller, more powerful and more mobile devices, traditional metal circuits on silicon are becoming too small to operate properly, and manufacturing techniques are too unwieldy to arrange the circuits accurately. "Soon we won't be able to manufacture any smaller because we won't be able to scratch patterns. The wavelengths of light we use are reaching their limitations," says Tomanek.

While the semiconductor industry has perfected techniques for etching microelectronic circuits onto silicon chips using lasers or beams of ions, new skills and more miniaturization are required to build in the nano-world. And to be truly effective, it will be necessary to build in three dimensions; today's microelectronic circuits are essentially scratched-out, two-dimensional pictures.